1. Field of the Invention
This invention relates to a combination tool, namely a wrench adaptor, usable either as a manually operated tool or as a tool adaptor usable with a wrench or a torque wrench. The wrench adaptor is especially designed to ease connect and disconnect of the subminiature, version A (SMA) connections in constrained spaces while allowing manual operation or the use of a standard torque wrench. The channel design of the wrench adaptor accommodating the cable allows access to SMA connectors without the need for bending or moving the cables thus protecting the coaxial cables and connectors therefor. The adaptor protects rigid and semi-rigid radio frequency (RF) cables during installation and removal and moves the application of rotational forces—whether by hand or by wrench—away from the faceplane of the mounting panel. More particularly, the invention pertains to a tool suited for use with high density, miniature RF connectors.
2. Description of the Prior Art
RF shielded connections to and from RF devices/components to RF test equipments/RF systems are commonly achieved by use of RF shielded cables with SMA connectors. The cable connection to the RF devices/components and/or to RF test equipment/RF systems is achieved by use of SMA male and female mating connectors which are already a part of the cables and the connection points.
The cables, more accurately referred to as “coaxial” or “shielded” cables, have a portion of the structure crimped or soldered to the connector, which connection usually is protected by a sleeve adjacent to and external to the connector. The protective sleeve is, in turn, shrink fitted and renders the cable end proximal to the SMA connector either semi-rigid or rigid. In the prior art, the installation connection is completed by using a torque wrench to tighten the nut, with the inside threads at the end of the male SMA connector, to the outside threads connector at a specific torque level. The number of cables and connections limit the space between connection points thus not allowing, or making it very difficult, to get wrench access to individual connection points for connection or disconnection.
The novelty and usefulness of the improved wrench action of the present invention is further enhanced because of the adoption by the microwave components industry of standardized RF accessories. Historically, the standardization was led by military specifications and later by industry standards. The wrench adaptor is used with standardized SMA connectors for coaxial cables as set forth in the Military Specifications—MIL-C-39012, now MIL-PRF-39012. The presently presented wrench adaptor accommodates the standard size cables, supporting the most popular size cable (8 mm) as well as the smaller 6.35 mm and larger up to 12 mm size cables and all cables therebetween. The flexibility of the wrench adaptor provides a single tool adapted to serve multiple coaxial cable connectors.
U.S. Pat. No. 7,080,581 discloses a tool provided for use with the connectors in high density environment. The internal area of this tool has a relatively narrow slot making it difficult to position and align the cable, especially when it is bent in the rear adjacent the male coaxial cable connector. The distal end of this prior art tool is occupied by a torque applying and torque limiting mechanism which requires the cable to exit the receiving channel in the middle portion of the tool and to form a bend in the cable. This tool is adapted to accommodate cables of relatively small diameter. In view of the restricted access to the inner space of the tool, it might be difficult to apply this tool to semi-rigid and rigid cables and to cables having exterior protective sleeves.
U.S. Pat. No. 7,946,199 discloses a coaxial cable connector rotation aid. Such connector nut rotation aid is for use with manual installation and improves the manual rotation of the threaded nut required to securely connect a coaxial connector with a coaxial cable port or device without the use of a wrench. This device fails to improve installation in areas of high density cabling. Another manual use F-type connector is disclosed in U.S. Pat. No. 6,817,272. This F-Type Connector Installation and Removal Tool accommodates limited bending of the cable at the installation site, however the size of the tool and its proximity to the connection area limits its use in high density areas.
Other prior art modified wrench devices, such as those represented in U.S. Pat. Nos. 4,227,429 and 5,152,196, provide assistance in areas where interconnection points are located in difficult to reach locations. These devices, however, are unable to assist with SMA connections because the devices lack the ability to cradle the cable within the device.
Accordingly, there is a current need for a simple, reliable and inexpensive tool for connecting and disconnecting SMA connectors that is operable in confined spaces and provides for setting the desired torque. There is also a need for a tool capable of (1) accommodating cables of various diameters; (2) operating to provide the torque required for the installation or removal of the connector; and, (3) during operation, maintaining semi-rigid and rigid cables in a static, protected condition. Such a tool should be usable in high density environments to properly torque each connector. Also the tool needs to be cost effectively manufactured in a variety of sizes for use with different standard hexagonal nut sizes.